1. Field of the Invention
This invention relates, generally, to devices and methods used when implanting tumor-fighting radioactive seeds in living tissue such as a prostate gland for therapeutic purposes. More particularly, it relates to a brachytherapy device having a simple structure and which houses a plurality of seeds in the absence of a seed magazine.
2. Description of the Prior Art
A co-pending disclosure by the present inventor, filed Dec. 12, 1997 bearing Ser. No. 08/989,727, and entitled "Interstitial Brachytherapy Device And Method" is believed to be the prior art most pertinent to this disclosure.
In the earlier invention, a plurality of vertically stacked radioactive seeds are loaded into a magazine. A highly novel bias means is used to urge the seeds, sequentially, into a discharge chamber of the magazine. A hollow needle and a plunger rod are then used to deposit one or more seeds into the prostate gland.
A drawback of the just-mentioned inventive device is that the magazine and the bias means are made of plastic and have some bulk; although plastic is inexpensive, a device made with less plastic would be less expensive. Moreover, the earlier device, although of simple construction, nonetheless has some mechanical complexity. What is needed, then, is a seed-implanting device that uses less materials, which is very simple in structure, yet which performs the same function as said earlier invention.
However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in this art how these needs could be met.